CN101500359A - Direct-current power supply device, power supply device for driving LED and semiconductor integrated circuit for driving power supply - Google Patents
Direct-current power supply device, power supply device for driving LED and semiconductor integrated circuit for driving power supply Download PDFInfo
- Publication number
- CN101500359A CN101500359A CNA2009100023445A CN200910002344A CN101500359A CN 101500359 A CN101500359 A CN 101500359A CN A2009100023445 A CNA2009100023445 A CN A2009100023445A CN 200910002344 A CN200910002344 A CN 200910002344A CN 101500359 A CN101500359 A CN 101500359A
- Authority
- CN
- China
- Prior art keywords
- current
- output
- signal
- variable
- control circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/10—Controlling the intensity of the light
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/37—Converter circuits
- H05B45/3725—Switched mode power supply [SMPS]
- H05B45/38—Switched mode power supply [SMPS] using boost topology
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/30—Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
Abstract
Disclosed is a direct-current power supply device, a power supply device for driving LED and a semiconductor integrated circuit for driving power supply including: a switching element (SW1) to intermittently supply a current to the inductor; an rectifying element to connect the inductor and an output terminal; a drive circuit to generate the drive signal of the switch element; a PFM comparator to generate a pulse signal having a pulse width corresponding to a voltage proportional to an output current of the external unit. A duty control circuit to generate a pulse signal by controlling a pulse width of an oscillation signal having a predetermined frequency in response to a current control signal is arranged in the direct-current power supply device. The pulse width output from the duty control circuit is provided for the drive circuit to generate the drive signal for the switch element in the period that the output of the PFM comparator is predetermined level.
Description
Technical field
The present invention relates to produce LED and drive the continuous-current plant of using supply voltage, for example relate to the switching power unit of the driving power voltage that effectively is used in the WLED (white light-emitting diode) that uses in the backlight liquid crystal display lamp that is created in pocket telephone and constitute the technology of the power drives of this switching power unit with semiconductor integrated circuit.
Background technology
In mobile devices such as pocket telephone, in the backlight of the liquid crystal panel that shows usefulness, used WLED, the general DC-DC transducer that uses by switching regulaor (switching regulator) formation of booster type in the supply unit of the driving power voltage that produces WLED.In driving with supply unit, this LED carries out following FEEDBACK CONTROL: the drive current of LED is converted to voltage feeds back to control circuit, compare by error amplifier and reference voltage, generation has the driving pulse of the pulse duration corresponding with potential difference, the switch element of electric current is flow through in driving on inductor (coil) discontinuous ground, drive current is maintained fixed.As driving with the relevant invention of supply unit, the invention of putting down in writing in the patent documentation 1 is for example arranged with this LED.
[patent documentation 1] spy opens the 2007-220855 communique
Summary of the invention
In mobile device, the function of the brightness of the backlight of the interim change of requirement sometimes ground liquid crystal panel.As switching the LED driving supply unit that brightness is drive current, the applicant's exploitation also works out the LED driving supply unit with structure shown in Figure 11.
The LED of Figure 11 drives and is provided with voltage and the reference voltage Vref 1 that will be fed the terminal FBBL of output current with supply unit and compares, export the signal with pulse duration corresponding with potential difference PFM (pulse frequency modulated) comparator 11, can control the control circuit of duty ratio 13 of pulse duration of the oscillator signal of preset frequency.This LED drive with supply unit only described PFM comparator 11 be output as predetermined level during, will offer drive circuit 15 from the pulse signal of control circuit of duty ratio 13 outputs, generate the drive signal of switch element.
The LED of Figure 11 drives and uses supply unit, when slowly reducing the drive current of LED according to current controling signal (control code) CC from the outside, obviously there is following problem: as shown in figure 12, the pulse period of the drive signal S1 of switch element prolongs gradually, frequency drop to the human range of audibility the upper limit, be below the 20kHz, perhaps as shown in figure 13, variation (so-called fluctuation (the ripple)) increase that output voltage V out takes place sometimes waits unfavorable situation aspect the characteristic of equipment.
This invention is conceived to the problems referred to above, and the following and LED that can reduce the fluctuation of output voltage of the upper limit that its purpose is to provide the frequency of the drive signal that can make switch element not to be reduced to the range of audibility drives with supply unit and power drives semiconductor integrated circuit.
In order to reach above-mentioned purpose, the invention provides a kind of switching regulaor (LED drives and uses supply unit), possess: the switch element that flows through electric current on inductor discontinuous ground; The rectifier cell that between described inductor and lead-out terminal, connects; Generate the drive circuit of the drive signal of described switch element; And be fed with the proportional voltage of output current, and output have PFM comparator with the signal of the corresponding pulse duration of this voltage.This switching regulaor is characterised in that, be provided with the control circuit of duty ratio of pulse duration that to control the oscillator signal of preset frequency according to current controling signal, only described PFM comparator be output as predetermined level during, to offer described drive circuit from the pulse signal of described control circuit of duty ratio output, generate the drive signal of described switch element.
More specifically, use supply unit, possess: the switch element that flows through electric current on inductor discontinuous ground as a kind of LED driving; The rectifier cell that between described inductor and lead-out terminal, connects; Generate the drive circuit of the drive signal of described switch element; And be fed with the proportional voltage of output current, and output have PFM comparator with the signal of the corresponding pulse duration of this voltage.Described LED drives and is characterised in that to have with supply unit: the variable current source of introducing the electric current that flows through described LED unit; And the control circuit of duty ratio of pulse duration that can control the oscillator signal of preset frequency according to current controling signal, described variable current source flows through the electric current corresponding with described current controling signal, described control circuit of duty ratio, when described current controling signal request is less flow through output current, compare when flowing through output current with request morely, the pulse duration of output is narrowed down, only described PFM comparator be output as predetermined level during, to offer described drive circuit from the pulse signal of described control circuit of duty ratio output, generate the drive signal of described switch element.
According to said structure, the ON time of switch element shortens when output current reduces, therefore, even output current reduces, the cycle of the output pulse of PFM comparator can not prolong terrifically yet, avoid the frequency of drive signal to drop to below the upper limit of the human range of audibility thus, and can reduce the fluctuation of output voltage.
At this, preferred described control circuit of duty ratio possesses: the capacity cell that constitutes second variable current source that flows through the electric current corresponding, is connected in series with this second variable current source with described current controling signal, described second variable current source and described capacity cell in conjunction with node on the switch of the discharge usefulness that is connected and more described in conjunction with the current potential of node and the comparator of predetermined reference voltage.Carry out conducting, end control by the switch of described oscillator signal to described discharge usefulness, described variable current source when described current controling signal request is less flow through output current, is compared when flowing through output current with request morely, and the electric current that flows through increases.
Perhaps, replace described second variable current source and use constant current source, and the variable voltage element of output and current controling signal corresponding reference voltage is set, variable voltage element, when described current controling signal request is less flow through output current, compare when flowing through output current with request, the voltage of output reduces morely.In addition, replace described second variable current source and use constant current source, replace capacity cell and use variable-capacitance unit, variable-capacitance unit, when described current controling signal request is less flow through output current, to compare when flowing through output current with request morely, capacitance diminishes.
According to the present invention, has following effect: can realize to make the frequency of the drive signal of switch element not drop to below the upper limit of the range of audibility, and the LED that can reduce the fluctuation of output voltage drives with supply unit and power drives semiconductor integrated circuit.
Description of drawings
Fig. 1 is that the structured flowchart that LED of the present invention drives an execution mode using supply unit has been used in expression.
Fig. 2 is the circuit diagram of the concrete example of expression control circuit of duty ratio.
Fig. 3 is the sequential chart of action of the control circuit of duty ratio of presentation graphs 2.
Fig. 4 is that the LED of presentation graphs 1 drives the sequential chart with the action of supply unit.
Fig. 5 is the sequential chart that a part of interval of enlarged drawing 4 is represented on time orientation.
Fig. 6 is the circuit diagram of another structure example of expression control circuit of duty ratio.
Fig. 7 is the sequential chart of action of the control circuit of duty ratio of presentation graphs 6.
Fig. 8 is the circuit diagram of the another structure example of expression control circuit of duty ratio.
Fig. 9 is the sequential chart of action of the control circuit of duty ratio of presentation graphs 8.
Figure 10 is the circuit diagram of the concrete example of expression variable current source.
Figure 11 is illustrated in the structured flowchart that the LED that studies before the present invention drives an example of using supply unit.
Figure 12 is that the LED of expression Figure 11 drives the sequential chart with the action of supply unit.
Figure 13 is the sequential chart that a part of interval of amplification Figure 12 on time orientation is represented.
Symbol description
10: ON-OFF control circuit; The 11:PFM comparator; 12: oscillating circuit; 13: control circuit of duty ratio; 15: drive circuit; 21,22: variable current source; 23: constant current source; 24: the variable voltage circuit; 25: variable capacitance; The 30:LED unit; L1: coil (inductor); C1: filter capacitor; SW1: coil drive switching transistor
Embodiment
Below, preferred implementation of the present invention is described with reference to the accompanying drawings.
Fig. 1 has represented to use LED of the present invention and has driven an execution mode using supply unit.
The LED of present embodiment drives and use supply unit, by constituted the switching regulaor of booster type with lower member: at coil (inductor) L1 that connects with the series connection form between direct voltage terminal VDD and the earth point and the switching transistor SW1, the diode D1 that connects between described coil L1 and lead-out terminal OUT that are made of N-channel MOS FET (insulated-gate type field effect transistor), the filter capacitor C1 that connects between lead-out terminal OUT and earth point, switching transistor SW1 is carried out the ON-OFF control circuit 10 that conduction and cut-off is controlled.And, on lead-out terminal OUT, connected the LED unit 30 that constitutes of a plurality of white light-emitting diode WLED by the series connection form.
In addition, though do not limit especially, but in the present embodiment, above-mentioned ON-OFF control circuit 10 and switching transistor SW1 form as semiconductor integrated circuit (using IC hereinafter referred to as driving) on a semiconductor chip, coil L1 and diode D1 and filter capacitor C1 are made of discrete (discrete) parts, are connected above-mentioned driving with on the IC as adding element.
ON-OFF control circuit 10 is made of following each one: compare with feedback signal reference voltage Vref 1, generate the PFM comparator 11 of the pulse signal with pulse duration corresponding with potential difference (changeable frequency); Generate the oscillating circuit 12 of the signal psi osc of preset frequency; Generate the control circuit of duty ratio 13 of the signal of the pulse duration of wishing according to oscillator signal φ osc; With the output of the inversion signal of the output of PFM comparator 11 and control circuit of duty ratio 13 OR gate circuit 14 as input; Accept the output of OR gate circuit 14, generate the conducting of switching transistor SW1, by the drive circuit 15 of drive signal etc.
In addition, in driving, be provided with the feedback terminal FBBL of the cathode side terminal that connects above-mentioned light-emitting diode WLED with IC, and be provided with the variable current source 21 that is connected with this feedback terminal FBBL in IC inside, make the electric current that flows through light-emitting diode WLED flow through the interior variable current source 21 of IC.And, on feedback terminal FBBL, connected the reversed input terminal of the PFM comparator 11 that constitutes ON-OFF control circuit 10, the drive current of WLED is converted to voltage, be input to PFM comparator 11.
And, in driving, being provided with the terminal of input from the Current Control sign indicating number CC (current instruction value) of the supplies such as CPU of outside with IC, the electric current corresponding with the control code CC that provides to this terminal is provided above-mentioned variable current source 21.In this embodiment, above-mentioned control code CC also is provided for control circuit of duty ratio 13, and control circuit of duty ratio 13 makes the pulse width variation of the pulse of output according to the current value of variable current source 21.Particularly, control circuit of duty ratio 13 carries out following action: the current value of variable current source 21 is big more, makes the pulse duration of output pulse wide more, and the current value of variable current source 21 is more little, makes the pulse duration of output pulse narrow more.
Thus, when current instruction value diminishes, when reducing the drive current of WLED, pulse duration narrows down, and the ON time of switching transistor SW1 shortens, and the magnitude of current once that flows through coil L1 reduces, therefore, compare with the situation of not carrying out the pulse duration control corresponding with current instruction value, the cycle of the output of PFM comparator 11 does not prolong, and the frequency of the conducting pulse of switching transistor SW1 does not reduce yet.
The concrete circuit example of in Fig. 2, having represented control circuit of duty ratio 13.The control circuit of duty ratio 13 of this embodiment is made of following each one: variable current source 22 that is connected in series between power supply voltage terminal VDD and earth point and capacitor C2; The switch MOS FET SW2 of the discharge usefulness that is connected in parallel with capacitor C2; Compare variable current source 22 and the current potential V2 of the connected node N2 of capacitor C2 and the comparator C MP2 of reference voltage Vref 2.
On the gate terminal of above-mentioned switch MOS FET SW2, applied the oscillator signal φ osc that comes self-oscillating circuit 12, at φ osc is that SW2 is ended in low level interval, electric current by variable current source 22 charges capacitor C2, the current potential V2 of node N2 rises gradually, φ osc be high level during with the SW2 conducting, the electric charge of capacitor C2 is discharged, and the current potential V2 zigzag ground of node N2 changes.By come relatively this waveform and reference voltage Vref 2 with comparator C MP2, as shown in Figure 3, generate the square wave have with the pulse duration of the corresponding hope of level of the slope of sawtooth waveforms and reference voltage Vref 2.In oscillator signal φ osc, use for example signal of the such frequency of 1MHz.
In the control circuit of duty ratio 13 of this embodiment, the current value of variable current source 22 is according to control code CC and phasic Chang, thus as shown in phantom in Figure 3, the slope variation of sawtooth waveforms, corresponding with it, the pulse width variation of output square wave.Particularly, the current value of variable current source 22 is big more, and the slope of sawtooth waveforms is big more, and the pulse duration of square wave is narrow more.In addition, the relation of the current value of the variable current source 21 corresponding with control code CC and the current value of variable current source 22 is opposite, and CC constitutes with control code, and when increasing the current value of variable current source 21, the current value of variable current source 22 reduces.
Next, use Fig. 4 and Fig. 5, with Figure 12 and Figure 13 compare on one side, the LED of key diagram 1 drives the action with supply unit on one side.In addition, Fig. 5 is the figure that a part of interval of enlarged drawing 4 is represented on time orientation, and Figure 13 is the figure that a part of interval of amplification Figure 12 on time orientation is represented.
Shown in Figure 12 (A), when control code CC switches to the sense of current that reduces LED, in the supply unit of the such structure of Figure 11, shown in Figure 12 (C), the cycle of the output of PFM comparator 11 prolongs gradually, and the width of pulse (between high period) broadens, only OR door 14 passes through the pulse of control circuit of duty ratio 13 between low period, therefore, the driving pulse of switching transistor SW1 broadens shown in Figure 12 (D) at interval gradually.Consequently might to reach the upper limit of the human range of audibility be below the 20kHz to the frequency of driving pulse, and shown in Figure 13 (E), the fluctuation of output voltage V out also increases.
Relative with it, in the supply unit of Fig. 1, even control code CC switches to the sense of current that reduces LED, shown in Fig. 4 (C), the cycle of the output of PFM comparator 11 does not prolong yet, and the width of pulse (between high period) does not broaden yet.This be because, when current instruction value reduces, shown in Fig. 4 (B), the narrowed width of the output pulse of control circuit of duty ratio 13, the ON time of switching transistor SW1 shortens, and drives the magnitude of current that flows through coil L1 by a conducting and reduces.
And even current instruction value reduces the also overtime not of cycle of the output of PFM comparator 11 as mentioned above, shown in Fig. 4 (D), the interval of the driving pulse of switching transistor SW1 also less broadens.Consequently can not reach the upper limit of the human range of audibility be below the 20kHz to the frequency of driving pulse, and shown in Fig. 5 (E), the fluctuation of output voltage V out also reduces.
Other structure example of in Fig. 6 and Fig. 8, having represented above-mentioned control circuit of duty ratio 13.
Wherein, the control circuit of duty ratio of Fig. 6, the variable current source 22 in the circuit of use constant current source 23 replacement Fig. 2, and be provided with variable voltage circuit 24 replacement reference voltage Vref 2.Variable voltage circuit 24 is considered to be constructed as follows structure: have the terraced resistance of a plurality of resistance that for example have been connected in series and a plurality of switches that are provided with in parallel with each resistance, and by optionally making these switches become conducting or cut-off state with described control code CC, produce with suitable subtend than (subtend than) with reference voltage Vref 2 dividing potential drops and voltage.
This circuit is controlled when control code CC switches to the sense of current that reduces LED, reduces so that offer the reference voltage Vref 2 of comparator C MP.Thus, as shown in phantom in Figure 7, the narrowed width of the output pulse of control circuit of duty ratio has the supply unit identical functions with the execution mode of Fig. 1.
On the other hand, the control circuit of duty ratio of Fig. 8 has used constant current source 23 to replace variable current source 22 in the circuit of Fig. 3, and is provided with variable capacitance 25 and replaces capacitor C2.Variable capacitance 25 is considered to be constructed as follows structure: for example have the capacity cell of a plurality of forms arranged side by side and a plurality of switches that are connected in series with each capacity cell, and by optionally making these switches become conducting or cut-off state with described control code CC, the quantity of switching the capacity cell that is connected with node N2 makes capacitance variation.
This circuit is controlled when control code CC switches to the sense of current that reduces LED, so that the minimizing of the quantity of the capacity cell that is connected with node N2, thereby capacitance is reduced.Thus, as shown in phantom in Figure 9, the slope steepening of the current potential V2 of node N2, the narrowed width of the output pulse of control circuit of duty ratio has the supply unit identical functions with the execution mode of Fig. 1.
The concrete circuit diagram of expression variable current source 21 in Figure 10.The variable current source 21 of this embodiment is by constituting with lower member: the MOSFET Q0 of the current-voltage conversion usefulness that constant current source I0 and series connection with it connect; N MOSFET Q1, Q2...Qn that current mirror (current mirror) is connected have been carried out with this MOSFET Q0; The n that between feedback terminal FBBL and earth point, is connected in series respectively switch MOS FET Q11～Q1n with Q1～Qn.In Q1～Qn, flow through corresponding to its electric current with the size ratio of Q0.
And, on the gate terminal of above-mentioned switch MOS FET Q11～Q1n, apply each bit signal B1～Bn of control code CC, switch total current by changing by the quantity of the MOSFET of B1～Bn conducting.Q1～Qn and Q11～Q1n all are N-channel MOS FET.Variable current source 22 in the control circuit of duty ratio of Fig. 2 can become following circuit: have and the laterally zygomorphic structure of the circuit of Figure 10, use the P channel mosfet as Q1～Qn and Q11～Q1n, the source electrode of Q1～Qn replaces linking to each other with earth point and linking to each other with supply voltage VDD.
More than, understand the invention that the inventor proposes specifically according to execution mode, but the present invention is not limited to above-mentioned execution mode.For example, in the supply unit of Fig. 1, in driving, be provided with oscillating circuit 12, but also can constitute the oscillator signal that input generates in chip exterior with IC.In addition, in Fig. 1, used MOSFET, but also can use bipolar transistor as switch element SW1.
And, in said embodiment, represented in the IC chip, to form the example that constitutes the switching transistor SW1 of switching regulaor, but, therefore also can be used as the element that adds and connect owing to flow through bigger electric current in this transistor.In addition, constituting from the outside input in IC in the driving of embodiment provides the control code CC of the command value of drive current, but also can replace control code and provide current instruction value by analog signal.
Utilizability on the industry
Illustrated in the above description in LED drives with supply unit and used example of the present invention, But the invention is not restricted to this, can be widely used in wanting to produce the voltage after boosting, and output current is advanced The supply unit of row FEEDBACK CONTROL.
Claims (6)
1. a continuous-current plant possesses: the switch element that flows through electric current on inductor discontinuous ground; The rectifier cell that between described inductor and lead-out terminal, connects; Generate the drive circuit of the drive signal of described switch element; And be fed with the proportional voltage of output current, and output have PFM comparator with the signal of the corresponding pulse duration of this voltage,
Described continuous-current plant is characterised in that,
Have: can be according to the current controling signal that provides from the outside, control the control circuit of duty ratio of pulse duration of the oscillator signal of preset frequency,
Only described PFM comparator be output as predetermined level during, will offer described drive circuit from the pulse signal of described control circuit of duty ratio output, generate the drive signal of described switch element.
2. a LED drives and uses supply unit, possesses: the switch element that flows through electric current on inductor discontinuous ground; The rectifier cell that between described inductor and lead-out terminal, connects; Generate the drive circuit of the drive signal of described switch element; And be fed with the proportional voltage of output current, and output have PFM comparator with the signal of the corresponding pulse duration of this voltage,
With LED unit that described lead-out terminal is connected in flow through drive current,
Described LED drives and is characterised in that with supply unit,
Have: the variable current source of introducing the electric current that flows through described LED unit; And
Can control the control circuit of duty ratio of pulse duration of the oscillator signal of preset frequency according to current controling signal,
Described variable current source flows through the electric current corresponding with described current controling signal,
Described control circuit of duty ratio when described current controling signal request is less flow through output current, is compared when flowing through output current with request morely, and the pulse duration of output is narrowed down,
Only described PFM comparator be output as predetermined level during, will offer described drive circuit from the pulse signal of described control circuit of duty ratio output, generate the drive signal of described switch element.
3. LED according to claim 2 drives and uses supply unit, it is characterized in that,
Described control circuit of duty ratio possesses: constitute second variable current source that flows through the electric current corresponding with described current controling signal; The capacity cell that is connected in series with this second variable current source; Described second variable current source and described capacity cell in conjunction with node on the switch of the discharge usefulness that is connected; And more described in conjunction with the current potential of node and the comparator of predetermined reference voltage,
By described oscillator signal, to the switch of described discharge usefulness carry out conducting, by control,
Described variable current source when described current controling signal request is less flow through output current, is compared when flowing through output current with request morely, and the electric current that flows through increases.
4. LED according to claim 2 drives and uses supply unit, it is characterized in that,
Described control circuit of duty ratio possesses: constitute the constant current source that flows through the electric current corresponding with described current controling signal; The capacity cell that is connected in series with this constant current source; Described constant current source and described capacity cell in conjunction with node on the switch of the discharge usefulness that is connected; The variable voltage element of output and described current controling signal corresponding reference voltage; And more described in conjunction with the current potential of node and the comparator of the reference voltage of exporting from described variable voltage element,
By described oscillator signal, to the switch of described discharge usefulness carry out conducting, by control,
Described variable voltage element when described current controling signal request is less flow through output current, is compared when flowing through output current with request morely, and the voltage of output reduces.
5. LED according to claim 2 drives and uses supply unit, it is characterized in that,
Described control circuit of duty ratio possesses: constitute the constant current source that flows through the electric current corresponding with described current controling signal; The variable-capacitance unit that is connected in series with this constant current source; Described constant current source and described variable-capacitance unit in conjunction with node on the switch of the discharge usefulness that is connected; And more described in conjunction with the current potential of node and the comparator of predetermined reference voltage,
By described oscillator signal, to the switch of described discharge usefulness carry out conducting, by control,
Described variable-capacitance unit when described current controling signal request is less flow through output current, is compared when flowing through output current with request morely, and capacitance diminishes.
6. a power drives semiconductor integrated circuit possesses: the switch element that flows through electric current on inductor discontinuous ground; Generate the drive circuit of the drive signal of described switch element; Be fed with the proportional voltage of output current, and output have PFM comparator with the signal of the corresponding pulse duration of this voltage,
This power drives is characterised in that with semiconductor integrated circuit,
Have: the outside terminal that is fed output current;
Link to each other with this outside terminal and introduce the variable current source of described output current; And
Can control the control circuit of duty ratio of pulse duration of the oscillator signal of preset frequency according to current controling signal,
Described variable current source flows through the electric current corresponding with described current controling signal,
Described control circuit of duty ratio when described current controling signal request is less flow through output current, is compared when flowing through output current with request morely, the pulse duration of exporting narrowed down,
Only described PFM comparator be output as predetermined level during, will offer described drive circuit from the pulse signal of described control circuit of duty ratio output, generate the drive signal of described switch element.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008-001356 | 2008-01-08 | ||
| JP2008001356A JP5211699B2 (en) | 2008-01-08 | 2008-01-08 | DC power supply, LED drive power supply, and power supply semiconductor integrated circuit |
| JP2008001356 | 2008-01-08 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101500359A true CN101500359A (en) | 2009-08-05 |
| CN101500359B CN101500359B (en) | 2013-11-20 |
Family
ID=40651532
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009100023445A Active CN101500359B (en) | 2008-01-08 | 2009-01-07 | Direct-current power supply device, power supply device for driving LED and semiconductor integrated circuit for driving power supply |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US7977889B2 (en) |
| EP (1) | EP2079157A2 (en) |
| JP (1) | JP5211699B2 (en) |
| CN (1) | CN101500359B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102378450A (en) * | 2010-08-23 | 2012-03-14 | 夏普株式会社 | Led driver circuit and led lighting device using the same |
| CN102573209A (en) * | 2010-10-28 | 2012-07-11 | 三美电机株式会社 | Lighting power supply device and method for controlling holding current |
| CN102739018A (en) * | 2011-03-30 | 2012-10-17 | 英飞凌科技股份有限公司 | Burst-mode operation of a switching converter |
| CN103199089A (en) * | 2013-03-29 | 2013-07-10 | 深圳市明微电子股份有限公司 | Rectifier and semiconductor integrated circuit |
| CN102056363B (en) * | 2009-11-11 | 2014-07-09 | 海洋王照明科技股份有限公司 | LED power driving circuit |
| CN104080247A (en) * | 2009-11-09 | 2014-10-01 | 东芝照明技术株式会社 | Integrated circuit, power supply device and illuminating device |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8742677B2 (en) | 2010-01-11 | 2014-06-03 | System General Corp. | LED drive circuit with a programmable input for LED lighting |
| CN102448214A (en) * | 2010-10-13 | 2012-05-09 | 飞虹高科股份有限公司 | Power management circuit and control circuit thereof |
| JP5495349B2 (en) | 2010-10-22 | 2014-05-21 | Ｎｅｃディスプレイソリューションズ株式会社 | LCD monitor |
| JP5667892B2 (en) * | 2011-01-20 | 2015-02-12 | ローム株式会社 | LOAD DRIVE DEVICE AND ELECTRONIC DEVICE USING THE SAME |
| WO2012132389A1 (en) * | 2011-03-31 | 2012-10-04 | シャープ株式会社 | Backlight system |
| CN102231927B (en) * | 2011-06-17 | 2013-10-02 | 四川仪岛科技有限公司 | LED module driving power |
| CN103152949A (en) * | 2013-03-11 | 2013-06-12 | 矽力杰半导体技术(杭州)有限公司 | Capacitance buck type light emitting diode (LED) driver and capacitance buck type LED driving method |
| WO2014174159A1 (en) | 2013-04-24 | 2014-10-30 | Societe D'etudes Et D'economies En Eclairage, Se3 | Device for supplying direct current for a set of led-based lighting devices used in industrial lighting and tertiary lighting |
| EP2822358B1 (en) | 2013-07-05 | 2017-05-31 | Ams Ag | Electric driver circuit for driving a light-emitting diode and method thereof |
| CN105915068B (en) * | 2016-04-29 | 2019-01-25 | 福建龙净环保股份有限公司 | A kind of dedusting power control method, apparatus and system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1815865A (en) * | 2005-01-31 | 2006-08-09 | 台湾类比科技股份有限公司 | DC-toDC. boost converting device and method |
| JP2007220855A (en) * | 2006-02-16 | 2007-08-30 | Matsushita Electric Ind Co Ltd | Led lighting circuit |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005026431A (en) * | 2003-07-01 | 2005-01-27 | Hunet Inc | Light emitting diode driving circuit |
| WO2007080777A1 (en) * | 2006-01-10 | 2007-07-19 | Rohm Co., Ltd. | Power supply device and electronic device provided with same |
| US7906943B2 (en) * | 2007-12-20 | 2011-03-15 | Microsemi Corporation | Boost converter with adaptive coil peak current |
| JP4631916B2 (en) * | 2008-02-21 | 2011-02-16 | 日本テキサス・インスツルメンツ株式会社 | Boost DC-DC converter |
-
2008
- 2008-01-08 JP JP2008001356A patent/JP5211699B2/en active Active
-
2009
- 2009-01-05 EP EP09000048A patent/EP2079157A2/en not_active Withdrawn
- 2009-01-06 US US12/348,951 patent/US7977889B2/en active Active
- 2009-01-07 CN CN2009100023445A patent/CN101500359B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1815865A (en) * | 2005-01-31 | 2006-08-09 | 台湾类比科技股份有限公司 | DC-toDC. boost converting device and method |
| JP2007220855A (en) * | 2006-02-16 | 2007-08-30 | Matsushita Electric Ind Co Ltd | Led lighting circuit |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104080247A (en) * | 2009-11-09 | 2014-10-01 | 东芝照明技术株式会社 | Integrated circuit, power supply device and illuminating device |
| CN104080247B (en) * | 2009-11-09 | 2017-04-12 | 东芝照明技术株式会社 | Integrated circuit, power supply device and illuminating device |
| CN102056363B (en) * | 2009-11-11 | 2014-07-09 | 海洋王照明科技股份有限公司 | LED power driving circuit |
| CN102378450A (en) * | 2010-08-23 | 2012-03-14 | 夏普株式会社 | Led driver circuit and led lighting device using the same |
| CN102378450B (en) * | 2010-08-23 | 2014-10-29 | 夏普株式会社 | Led driver circuit and led lighting device using the same |
| CN102573209A (en) * | 2010-10-28 | 2012-07-11 | 三美电机株式会社 | Lighting power supply device and method for controlling holding current |
| CN102739018A (en) * | 2011-03-30 | 2012-10-17 | 英飞凌科技股份有限公司 | Burst-mode operation of a switching converter |
| CN102739018B (en) * | 2011-03-30 | 2015-03-11 | 英飞凌科技股份有限公司 | Burst-mode operation of a switching converter |
| CN103199089A (en) * | 2013-03-29 | 2013-07-10 | 深圳市明微电子股份有限公司 | Rectifier and semiconductor integrated circuit |
| CN103199089B (en) * | 2013-03-29 | 2015-12-02 | 深圳市明微电子股份有限公司 | Semiconductor integrated circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009164397A (en) | 2009-07-23 |
| US20090174347A1 (en) | 2009-07-09 |
| US7977889B2 (en) | 2011-07-12 |
| CN101500359B (en) | 2013-11-20 |
| JP5211699B2 (en) | 2013-06-12 |
| EP2079157A2 (en) | 2009-07-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101500359B (en) | Direct-current power supply device, power supply device for driving LED and semiconductor integrated circuit for driving power supply | |
| CN101500360B (en) | Direct-current power supply device, power supply device for driving LED and semiconductor integrated circuit for controlling power supply | |
| CN102238779B (en) | Control circuit for switching power supply, control method, light-emitting device and electronic device | |
| US6628252B2 (en) | LED drive circuit | |
| CN100388065C (en) | Power supply apparatus | |
| CN100546419C (en) | Luminescent system and LED driving circuit and method based on light-emitting diode | |
| CN102821511B (en) | Led drive circuit | |
| CN100440697C (en) | Drive circuit of charge pump circuit, power supply and light emitting device | |
| CN101199106A (en) | Step-up switching regulator and its control circuit and electronic apparatus employing it | |
| CN101389174A (en) | Inverter and control circuit, control method and luminescent device using the same | |
| US8884545B2 (en) | LED driving system and driving method thereof | |
| US8106901B2 (en) | Power circuit and liquid crystal display device using same | |
| CN201365305Y (en) | Power supply management circuit and television equipped therewith | |
| JP3284128B1 (en) | LED element driving circuit for illumination of display device in portable equipment | |
| US20080290734A1 (en) | Switching pulse generating circuit and regulator using the same | |
| CN114420057A (en) | Backlight power supply, display device and electronic equipment | |
| CN201142203Y (en) | LED driving circuit and LCD device with the same | |
| JPH0382364A (en) | Step-up/down chopper device | |
| CN103377631A (en) | Liquid crystal display device | |
| KR102103798B1 (en) | Method of driving light-source, light-source apparatus for performing the method and display apparatus having the light-source apparatus | |
| Nam et al. | A highly power-efficient LED backlight driving system for LCD TVs | |
| KR20010087004A (en) | Display Device with Low Power Scan Driver | |
| KR101056420B1 (en) | Step-down converter type LED driving circuit capable of directly detecting the voltage / current at the output stage | |
| KR101034899B1 (en) | Light-emitting diode driving circuit having step-up/down converter capable of direct detection of output voltage/current | |
| KR101287801B1 (en) | Device of driving lamp and display apparatus having the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |